Further analysis using KM indicated that higher PTGER1 expression was associated with a favourable prognosis in five cancers: breast invasive carcinoma (BRCA) (Log-rank p = 0.054, HR = 0.8), ESCA (Log-rank p = 0.014, HR = 0.45), HNSC (Log-rank p = 0.07, HR = 0.78), LIHC (Log-rank p = 0.004, HR = 0.6), and thyroid carcinoma (THCA) (Log-rank p = 0.0014, HR = 0.22). Here, PTGER1 is linked to thyroid gland carcinoma.